The present invention relates to devices that improve a pickup truck's aerodynamic flow that are placed into a pickup truck box, which is the cargo area of a pickup truck. The benefit of improving the pickup truck's aerodynamic flow is a reduction in aerodynamic drag and an increase in the pickup truck's fuel efficiency. More particularly, the present invention relates to producing an airfoil shape to improve the aerodynamic flow. An airfoil is known by those practicing in the field of aerodynamics as the preferred shape for producing the lowest aerodynamic drag. The airfoil design is especially effective at maintaining higher pressure in the trailing area of a moving object. Although a number of devices for improving a pickup truck's aerodynamic flow have been proposed in the prior art, none are as effective as the present invention.
Various prior art devices have been provided to fully cover or partially cover a pickup truck box in order to improve aerodynamic flow. One common device is a tonneau cover. A tonneau cover may be constructed from wood, metal, cloth, or composite; it extends from the rear of the truck cab to the truck tailgate and from both sides of the pickup truck box, covering the top of the sides of the pickup truck box and the top of the tailgate. Although tests have shown that the tonneau cover improves aerodynamic flow, and thus increases the pickup truck's fuel efficiency, the tonneau cover is not as effective as the present invention. Specifically, the tonneau cover does not improve the aerodynamic flow in the trailing area of the cab and tailgate, where a low-pressure area exists. In general, low-pressure in the trailing area of a moving object creates a drag force opposing the forward motion.
Other prior art solutions to improve aerodynamic flow are devices to be placed into the pickup truck box in front of the tailgate. Many of these devices are known as wind deflectors or enhanced aerodynamic devices. These devices claim to improve aerodynamic flow over the tailgate by modifying the leading area from a flat vertical surface to an inclined surface or curved surface. However, these devices also fall short of improving aerodynamic flow, because they do not improve the trailing area aerodynamic flow behind the cab and the tailgate.
Other prior art solutions have been suggested. For example, one prior art solution suggests a cover attached to each of the sidewalls inside the truck box to eliminate the wheel well protruding into the air flow. And another prior art solution suggests attaching rear spoilers on top of the tailgate, which are curved vanes believed to smooth the aerodynamic flow over the top of the tailgate. However, these solutions do not improve the aerodynamic flow in the trailing areas of the cab and the tailgate.
A known technique believed to improve aerodynamic flow in a pickup truck is the removal of the tailgate. Although this removes the tailgate from the flow path, and therefore eliminates lower pressure behind the tailgate as well as removes an airflow obstruction, airflow behind the cab is actually made worse when this technique is implemented. The trailing area of the cab is now larger, which creates an even lower pressure, and thus, increased aerodynamic drag. Furthermore, removing the tailgate is not always desired, for example if the pickup truck box is not completely empty.
In view of the foregoing, there is a need for improved techniques for improving the aerodynamic flow of a pickup truck by mitigating or eliminating low pressures behind the cab and behind the tailgate.
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.